. >> narrator: obama arrived in chicago after the election of the city's first black mayor, harold washington. >> ...have joined hands to form a new democratic coalition... (applause and cheers) >> i think that the fact that chicago had elected an african-american mayor in harold washington sort of emphasized with barack that he was coming to a city where blacks were a major presence and had some significance. >> narrator: washington's politics were a living example of what obama was looking for. >> what washington was able to do was to put together these coalitions-- african-americans, latinos and progressive whites. and he was able to pull that together and beat the machine. >> god bless you all and thank you from the bottom of my heart. >> and that kind of coalition building was incredibly influential for barack. >> narrator: obama's laboratory would be the city's south side. >> we had put an ad in a number of newspapers for a community organizer in the south side of chicago. i'm looking for anybody who might be a good organizer, but i particularly need somebody who's african-american. >>